For the production of granules of plastics material and similar products, the material brought into the plastic state is extruded in the form of threads, cut after extrusion into small cylindrical portions by means of rotating blades in contact with the die.
For carrying out such an operation, an extruder is filled suitable for plasticizing the material to be formed into granules, a die plate having a plurality of holes adapted for forming the aforementioned threads.
For the purpose of preventing the holes of the guide plate from being subjected to wear, as a consequence of the abrasion of the extruded material and due to the scraping of the blades, these holes are equipped with inserts of a material of high hardness, for example tungsten carbide, usually secured to the plate by braze welding.
This fixing technique, however, is not always capable of assuring the required locking effect, thus making possible detachment of an insert from its seating during working as a consequene of its axial pulling-out caused by the friction of the extruded material.
It is also possible to secure the inserts in the associated seatings by screwing or the like, but this requires tiresome additional operations, which make the construction of the die plate excessively expensive and, in particular, require excessive length of the final extrusion holes.